Buggy code:
public { - 0.346039 , 0.392619 } , new double [ ] { - 0.280579 , 0.444306 } , new double [ ] { - 0.216035 , 0.470009 } , new double [ ] { - 0.149127 , 0.493832 } , new double [ ] { - 0.075133 , 0.483271 } , new double [ ] { - 0.007759 , 0.45268 } , new double [ ] { 0.060071 , 0.410235 } , new double [ ] { 0.103037 , 0.341076 } , new double [ ] { 0.118438 , 0.273884 } , new double [ ] { 0.131293 , 0.192201 } , new double [ ] { 0.115869 , 0.129797 } , new double [ ] { 0.072223 , 0.058396 } , new double [ ] { 0.022884 , 7.18E-4 } , new double [ ] { - 0.053355 , - 0.020405 } , new double [ ] { - 0.123584 , - 0.032451 } , new double [ ] { - 0.216248 , - 0.032862 } , new double [ ] { - 0.278592 , - 0.005008 } , new double [ ] { - 0.337655 , 0.056658 } , new double [ ] { - 0.385899 , 0.112526 } , new double [ ] { - 0.405517 , 0.186957 } , new double [ ] { - 0.415374 , 0.262071 } , new double [ ] { - 0.387482 , 0.343398 } , new double [ ] { - 0.347322 , 0.397943 } , new double [ ] { - 0.287623 , 0.458425 } , new double [ ] { - 0.223502 , 0.475513 } , new double [ ] { - 0.135352 , 0.478186 } , new double [ ] { - 0.061221 , 0.483371 } , new double [ ] { 0.003711 , 0.422737 } , new double [ ] { 0.065054 , 0.37583 } , new double [ ] { 0.108108 , 0.297099 } , new double [ ] { 0.123882 , 0.22285 } , new double [ ] { 0.117729 , 0.134382 } , new double [ ] { 0.085195 , 0.05682 } , new double [ ] { 0.0298 , - 0.019138 } , new double [ ] { - 0.02752 , - 0.072374 } , new double [ ] { - 0.102268 , - 0.091555 } , new double [ ] { - 0.200299 , - 0.106578 } , new double [ ] { - 0.292731 , - 0.091473 } , new double [ ] { - 0.356288 , - 0.051108 } , new double [ ] { - 0.420561 , 0.014926 } , new double [ ] { - 0.471036 , 0.074716 } , new double [ ] { - 0.488638 , 0.182508 } , new double [ ] { - 0.48599 , 0.254068 } , new double [ ] { - 0.463943 , 0.338438 } , new double [ ] { - 0.406453 , 0.404704 } , new double [ ] { - 0.334287 , 0.466119 } , new double [ ] { - 0.254244 , 0.503188 } , new double [ ] { - 0.161548 , 0.495769 } , new double [ ] { - 0.075733 , 0.49556 } , new double [ ] { 0.001375 , 0.434937 } , new double [ ] { 0.082787 , 0.385806 } , new double [ ] { 0.11549 , 0.323807 } , new double [ ] { 0.141089 , 0.22345 } , new double [ ] { 0.138693 , 0.131703 } , new double [ ] { 0.126415 , 0.049174 } , new double [ ] { 0.066518 , - 0.010217 } , new double [ ] { - 0.005184 , - 0.070647 } , new double [ ] { - 0.080985 , - 0.103635 } , new double [ ] { - 0.177377 , - 0.116887 } , new double [ ] { - 0.260628 , - 0.100258 } , new double [ ] { - 0.335756 , - 0.056251 } , new double [ ] { - 0.405195 , - 8.95E-4 } , new double [ ] { - 0.444937 , 0.085456 } , new double [ ] { - 0.484357 , 0.175597 } , new double [ ] { - 0.472453 , 0.248681 } , new double [ ] { - 0.43858 , 0.347463 } , new double [ ] { - 0.402304 , 0.422428 } , new double [ ] { - 0.326777 , 0.479438 } , new double [ ] { - 0.247797 , 0.505581 } , new double [ ] { - 0.152676 , 0.51938 } , new double [ ] { - 0.071754 , 0.516264 } , new double [ ] { 0.015942 , 0.472802 } , new double [ ] { 0.076608 , 0.419077 } , new double [ ] { 0.127673 , 0.330264 } , new double [ ] { 0.159951 , 0.26215 } , new double [ ] { 0.15353 , 0.172681 } , new double [ ] { 0.140653 , 0.089229 } , new double [ ] { 0.078666 , 0.024981 } , new double [ ] { 0.023807 , - 0.037022 } , new double [ ] { - 0.048837 , - 0.077056 } , new double [ ] { - 0.127729 , - 0.075338 } , new double [ ] { - 0.221271 , - 0.067526 } } ; public void doTestStRD ( final StatisticalReferenceDataset dataset , final LeastSquaresOptimizer optimizer , final double errParams , final double errParamsSd ) { } public void testKirby2 ( LeastSquaresOptimizer optimizer ) throws IOException { } public void testHahn1 ( LeastSquaresOptimizer optimizer ) throws IOException { } class LinearProblem { private final RealMatrix factors ; private final double [ ] target ; public LinearProblem ( double [ ] [ ] factors , double [ ] target ) { } public double [ ] getTarget ( ) { } public MultivariateVectorFunction getModelFunction ( ) { } public MultivariateMatrixFunction getModelFunctionJacobian ( ) { } public LeastSquaresBuilder getBuilder ( ) { } } }

Fix:
return new LeastSquaresBuilder ( ) . checkerPair ( new SimpleVectorValueChecker ( 1.0E-6 , 1.0E-6 ) ) . maxEvaluations ( 100 ) . maxIterations ( getMaxIterations ( ) ) ;